Hitherto, there has been known a pattern forming method in which a liquid material (ink) prepared through dispersion of metal particles or the like. in a solvent is ejected through a nozzle, and droplets of the liquid material are deposited onto an object on which a pattern is to be formed (hereinafter the object may be referred to as a “pattern formation object”), to thereby form a pattern; such as a conductive pattern or an insulation pattern, on the object. Such a method is a pattern forming method employing an ink-jet system or a dispenser system. As has also been known, such a pattern forming method is employed for formation of, for example, a conductive pattern of a gas sensor.
Meanwhile, for example, there has been known a pattern forming method utilizing an ink-jet printer employing, as a recording liquid, a UV ink exhibiting high viscosity at ambient temperature, in which method a UV ink contained in a recording head is heated to lower the viscosity of the ink, and droplets of the UV ink are deposited onto a pattern formation object, followed by cooling of the object for formation of a pattern (see, for example, Patent Document 1). However, this method relates to a technique unique to a pigment-containing color ink; i.e., a technique regarding suppression of fading of a printed image over a long period of time. That is, this method has no relation to a technique for forming a conductive pattern or the like from a liquid material containing, for example, metal particles.